Grey Render? Noobie question
Render layers

All your object are in the first and second render layer (you can see that by giving a look at the orange dots in the quick layer bar), while the only layer that will be rendered is the third (see the cursor location in the image below).

Is not immediately understandable, but the boxes under the Layer section in the Render Layer panel control the layers that should be rendered.



You just have to enable the layers with your objects. Shift+click the first and the second box.